There are presently ballasts for use in illuminating public and industrial lighting that can save power by using a relay that at certain hours of the night, when vehicular traffic and/or pedestrian or general activities have been decreased, disconnects a capacitance section of the circuit, so that the lamp current is reduced and therefore so does the power thereof, which brings about a reduction in electric power that the ballast bearing luminaire takes from the feeder line, even when the illumination diminishes.
The drawback of this ballast is that the relay mentioned above is operated by remote control through a pilot wire which joins all the ballasts and the signal of which is controlled from a remote place manually or by a clockwork mechanism.
In addition, the other drawback is that the principle of reduction of the strength of the lamp is by means of reducing the capacitance of the ballast, which only allows applying this principle to ballasts with self-transforming self-regulating circuits or regulated advanced circuits (CWA) which are the most expensive in the market.
The purpose of the invention is to eliminate the inconvenience of the installation of the pilot wire, as well as the clockwork mechanism, and also to be able to use ballasts with lower costs in the market, such as series reactor circuits (or inductances in series) by using the principle of inductance variation instead of capacitance variation to achieve the power savings.
The features of this ballast are shown in the following description and in the accompanying diagrams, the same reference signs serving to indicate the same parts in the shown FIGS.
With regard to the types of electric gas discharge lamps generally used, these are three: high-pressure sodium vapor lamps, low-pressure sodium vapor lamps, and those of mercury vapor.
The electric power-saving ballast described below can be used in two of the three types of lamp described above, which are the high-pressure sodium vapor and those of mercury vapor.
As regards the circuits, the power-saving ballast can be used in the regulated advanced circuit type, also known as self-transforming self-regulating or CWA, as well as in the series reactor circuits (inductance series).